Project modernization (#630)

* Fixed boats falling and a TP glitch #266

* Replaced every C-style cast with C++ ones

* Replaced every C-style cast with C++ ones

* Fixed boats falling and a TP glitch #266

* Updated NULL to nullptr and fixing some type issues

* Modernized and fixed a few bugs

- Replaced most instances of `NULL` with `nullptr`.
- Replaced most `shared_ptr(new ...)` with `make_shared`.
- Removed the `nullptr` macro as it was interfering with the actual nullptr keyword in some instances.

* Fixing more conflicts

* Replace int loops with size_t and start work on overrides

Minecraft.Client/stubs.h

@@ -170,15 +170,15 @@ class ZipFile
 {
 public:
 	ZipFile(File *file) {}
-	InputStream *getInputStream(ZipEntry *entry) { return NULL; }
-	ZipEntry *getEntry(const wstring& name) {return NULL;}
+	InputStream *getInputStream(ZipEntry *entry) { return nullptr; }
+	ZipEntry *getEntry(const wstring& name) {return nullptr;}
 	void close() {}
 };
 
 class ImageIO
 {
 public:
-	static BufferedImage *read(InputStream *in) { return NULL; }
+	static BufferedImage *read(InputStream *in) { return nullptr; }
 };
 
 class Keyboard